Hack saw



F. W. PIERCE HACK sAw June 9, 1925. 1,541,384

Filed June -6. 1925 v @Wee @WMM-W@ www Patented June 9, 1925.

ilhllTED `STATE isaiasi FREDEECK VJ. EIERCE, 0F SOMERVLLE, MASSACHUSETTS, ASSIGNR TO FREBEBICK V7. PIERCE 1N D BURG? H'. .MACYQ COPARTN ERS, 'DO NG BUSNESS AS THE-B-X-SAW' GOMEZ-KNX?, OFYBOSTON, MASSACHUSETTS.

HACK

Application filed .Tune 6,

To @ZZ wimmc' may conce/rn.:

Beit lin-own that I, FREDERICK Wl. Piimon, a citizen ot the United States, residing at Somerville, in the county oft Middlesex and State ot Massachusetts, have invented new and useful Improvements in Hack Saws, et which the 'following is a specification.

The present invention relates to haelt saws. the constituent elements olf which are a iolder and a detachable blade, andv has Ytor its objects to` provide means tor effecting easy and rapid attachment andl detachment oi the blader with and 'from the holder, to eiiect at t-he saine time a secure attachment of the blade with the holder not merely at the ends, but throughout its length as well, to enablevthe holder tor take different blades,

varying somewhat in length, and to securev such ditlerent blades equally lirinly without the aid of tension devices to limit the depth ot cut possible with the saw, and, in connection with such limitation, to permit cutting to different limits of depth without any intermediate adjustment otI the blade, and otherwise to improve the construction and useful qualities oil-such tools.

rlhe manner in which these objects areL accomplished is explained in connection with the detailed description of the preferred 'torni of my invention contained in the tollowing specification with reference to the drawings.

ln the drawings,-

Figure l is a perspective view on a large scale of the several parts of my improved hack saw, detached and separate from one another but in approximately the relative positions which they occupy when assembled. j

`Figure 2 is a side elevation of the assembled saw, shown on a smaller scale.

Figures 3 and el are cross sections on approximately the scale of Figure l, taken on the linesB-?) and 4 4 respectively of Fig ure 2. l

Lilie reference characters designate the same parts wherever they occur in yall the ligures. v

The saw comprises a detachable blade a and a holder; the holder consists oft two parts and c, which are preferably'bars oft' suiiiciently strong' and VVrigid materia-ly and term. best, material tor these members.

A handle Steel is a suitable, and indeed the.

1923. Serial No. 643,616.

cast iron or any other suitable material andV in alterni which enables it to be iirmly and;y

comfortably grasped by the user. 'Connection between the handle'and bar?) is made by providing` the handle with'an extension (Z whichv` overlaps one end otv .the bar and is secured thereto'by screws 7 or other 'suitablev tastenings. The handle is also formed with a shoulder (Z2 besides the extension d against/which the complementally toi-ined end ot vthe attached bar may abut in order to increase thel rigidity oi the connection between the bar and handle. Y

The bar c is ot similar outline to t-he bar L but is shorter by an amo-untsubstantially equal to the length ofV the extension d', wherebyit can be ylaid against the other bar, with the blade between them, and made fast by connections at opposite ends. nection at one end, preferably that remote trom the handle, ismade by a screw g which is passed through a hole in the` bar b, in which its shank may be turned freely, and

is threaded into a` tapped hole hin the bar c. rhe other fastening is a screw z' which passes through slots and c in the two bars and receives ar nut Z on the end whichV protrudes from bar-c.r Slots are provided in this manner for the fastening at one end in' order that the variations which-occur unavoidably, in the course oit' m`anutacture,'in the lengths and distances between the apertures ot blades put out commercially as of approximately the same dimensions, may

be accommodated without difficulty.

ne of the valuable and important novel features of this inventionis that the blade, instead ot' being formed with enclosed holes at its opposite ends to receive the tastenings, as hasbeen heretofore usual in hack saw construction, is formed with notches m and In, open through the back edge of the blade, that is, the edge opposite to the toothed edge, and are wide enough to receive the screws by lateral insertion, whereby the blade may be assembled with the holder by loosening the fasteners but .vith'out reni.I` ,thrn'i'trom The cono Vbetween the ends of the bars.

the holder.v Preferably, also, the mouths of the notches are widened to assist in nnding the fasteners when being assembled.

Another improvement, which makes possible the use of a saw blade having notches of the sort described, .is embodied in the holder itself and consists in the fact that either or both of the side bars, but preferably both, may be slightly bowed or cambered lengthwise. The character and approximate amount of this cambered formation is shown in Figure l by reference to the broken lines, which represent straight lines The curvature is such that, when the holder is assembled, the convex sides of the bars are adjacent to one another. It follows from this construction and arrangement that when the blade is inserted between the bars and the latter are drawn together by setting up the connecting screws, the pressure of the bars against the blade is exerted more or less alongthe length of the latter, whereby the blade is held firmly, notincrely at the points where direct clamping pressure is exerted by the fasteners, but at intermediate points well. By making the bars of spring tempered stock and with the proper amount of camber, as much gripping pressure may be exerted throughout the whole length of the blade, or at any selected point or points, as may be necessary for any use to which the saw is put, and the gripping effect is not confined wholly to the ends of the blade.

The side bars of the holder also serve as gauges to limit the depth of cut possible to be made. This effect is indicated in Figure l by the cutting back of the lower edges of the side bars, but it is more definitely shown in Figure 2. The edge of the bar4 I) vwhich serves as the gauge is there designated by the letter 0 and it is to be understood'that the-other bar c is or may begof the same character and form as to its lower edge. These stop 'shoulders or gauging edges are square to the sides of the blade and preferably extend through the full thickness of the bars, as shown in the sectional views Fig- 'ures and 1l. It will be noted in Figure 2 also thatthe gauge or stop shoulder formed by the lower edge of the bar is nearer the toothed edge of the blade at the outer end of the saw, and fartherfrom the saw teeth at the inner end; using the terms inner7 and outer here with reference to their distances from the handle'. Preferably also the gauge stop is formed with a continuous inclination from its shallowest to its deepest part, although this is a detail which may be modified; or the parts of different depths may be more or less nearly parallel with the toothed edge of the saw as far as they extend, and separated from one another by distinct shoulders. Affurther variation in the depth to which the saw may cut, is effected by adjustment of the saw blade in the holder to place its toothed edge at a greater or less distance from the gauge shoulders. Such an adjustment is made possible by the open notches m of the blade; and this is another lengths,and particularly without at the same .1

time destroying the insulationof the enclosed conductors.

lf, when the electrician is installing such conductors he needs to cut them, it is a wastel of his time if hehas to carry the conductor to some more or less distant point where there is a bench and proper tools. lt is much more economical of his time if he can be equipped to cut the'wire on the spot where, in the course of installing it, he finds it necessary to sever it. But with the tools Y heretofore used this has been a difficult proceeding because, lacking a bench and a vise to hold the wire, the'flexible character of thearmor causes it to bind and grip the blade of the ordinary hack saw and break it. Then, if the electrician succeeds in cutting through the armor, the lack of any protection on the ordinary hack saw gives rise to the danger of cutting through the soft insulation on the wire and either cutting the latter also or making a short circuit. Usually when such a wire is cut, it is necessary to leave a part of the insulated wire projecting from the armor, wherefore the severance of the armor and of the wire must take place at different points.

The saw just described overcomes these difficulties. The rigid manner in which the blade is held, for it is not only clamped at both ends, but is gripped at numerous points between the ends as well, and this prevents vibrations from being set up in the blade by the sawing action, prevents it from being broken if seized by the armor in the course of cutting, and this relieves the workman of having any care for the blade. He can place the armored wire across his knee and use all the strength needed to cut through the armor and can complete a cut in a very brief time, since the blade is practically unbreakable in its Vmounting. lThere is nov danger of cutting' through the `insulation because, in making this cut, he uses that part of the saw where the stop shoulder ill) 0 is nearest to the teeth of the blade, and there the depth of the cut is limited toless than the depth of the insulation from'vthe armor. But when it is necessary to cut through the wire as well,` he uses that part of the saw where the stop isf-arther bach from the teeth and oy-which he can cut through the `insulation and the embedded wire.

This capacity of the sameftool for cutting both the armor and the wire reduces the equipment which the worlnnanneeds to carry, and enables him Jto do with the saw what he would otherwise require cutting pliers in addition to accoi'nplish. Also, the construction of the saw, with the side bars close to the toothed edge, both keeps Vthe saw from jumping olf from the cut and protoets the operators hands.r Also the saw can be used iii-narrow spaces as in cutting olf old wiring from closets, outlet boxes, switch boxes, etc.

'lhe saw is useful vas-well for cutting flexible Ametallic conduit, the various malres of which are made substantially the same as the metallic armor of the corresponding makes of armored wires and cables. Hence, for the purposes of this specification and the protection which l claim the term armored conductor is intended to include also conduits for electrical purposes, whether occuiied or not by insulated conductors.

Vilhat l claim and desire to secure by Letters Patent is :V

l. An armored wire cutting tool comprising a blade having teeth on one edge and a holder having side bars constructed to bear ilatwise against the side of the blade and grip said blaue throughout its length, said bars being cut away at one edge to expose the toothed edge of the blade and said cut away edges being formed as stop shoulders ot the blade at projecting from the sides right angles thereto.

Q. rin armored wire cutting tool compris- 'ing a blade having teeth on one edge and a holder having side bars constructed to grip said blade throughout its length, said bars being cut awaY at one edge to expose the toothed edge of the blade and said cut away edges being formed as stop shoulders projecting from the sides of the blade at rightangles thereto and at a distance bach from said toothed edge substantially equal to the `lhielniess of the armor for at least a part of the lengt-h of the blade.

3. Ein armored wire cutting tool comprising a blade having teeth on one edge and a holder having side bars constructed to grip said blade throughout its length, said bars being out away at one edge to expose the toothed edge of the blade and said cut away edges being formed asstop shoulders projecting'from the sides of the blade at right angles thereto and at a distance baci;

' to 4draw themfrom said toothed edge substantially equal to the thickness of the armor for a part only of the length of the blade and being at a greater distance bach from such toothed edge throughout another part of the length of the blade,` Y f l.A An armored wire cutting tool lconsisting of a-blade having saw teeth on one edge, side bars arranged onl opposite sides of said blade, and fastening means engaged with said bars adjacent to the ends of the blade for drawing the bars into clamping relation to the blade, one of the side bars ybeing bowed or can bered toward the other whereby to eiert gripping pressure against the blade in the intermediate part Vas well as at the ends thereof. i

5. A hack sawv consisting. of` saw blade having lnotches near its opposite ends o1 ening through its bac-l.; edg sisting of side bars an., .fasteners passing from one such barfto theY other and adapted' y together, the blade being Vadapted for insertion'between the bars and the bar-s having faces which bear flatwise against the blade and grip it when so drawn together` its notches being spaced so as to pass over said fasteners when so assembled.

(S. 'l'iacl; saw comprising a bar having a handle at one end, a complemental bar lying beside the first named bar, one o said bars Ybeing' convex between its ends toward the other, engaged fastening devices with said bars adjacent to the ends of the latter for drawing them together, and a saw blade between said bars with its side faces in contact with the adjacent faces of the, bars and grippedy thereby, said fastening devices being arranged to exert force on the bars for the purpose set fort-h in lines which pass across the blade between the toothed edge and the back edge thereof, and the said couver; formation of one of the bars causing theblade to be so gripped throughont its lengt-h.

7. A hack saw comprising a bar having a handle at one end, a complemental bar adapted to be placed'beside the first named bar, one of said bars being convex between its ends toward the other, fastening screws passing through and engaged-with said bars for drawing them together, and a saw blade. adapted to be placed between .said bars and gripped thereby said blade having openings intermeoiate its toot-hed edge and its bach Athrough which .said screws pass and the said convex formation of one of the bars causing the blade to be so gripped throughout its length, both bars having their edges nearest to the toothed edge of the blade` made with a recessed formation so as to provide stop or gauge shoulders the surfaces of Awhich are substantially at right angles to the adjacent faces of the blade.

e, and a holder con-l 'lil llO

8. A hack saw comprising a. holderv and a saw blade, the holder being formed of tWo side bars, one of which is longer than the other, and a handle, said handleV being formed with an extension at one end overlapping one end of the longer bar and with a shoulder V.beside such extension against which the adjacent end of the bar may abut, the overlapping extension and `end ot tho bar beingl secured together and the blade being detaohably confined between said bars, ooinbined with fasten-ers holding the bars together and causing` them to grip the blade.

' 9. A hack .saw eon'iprising a toothed blade havingl fastener-reeeiving apertures near its ends, a holder provided with portions adapted to embrace the apertured parts of the blade, and fasteners arranged to'pass throughthe apertures of the blade and being connected with the holder; the holder being formed with an elongated slot to re ceive one ot said fasteners whereby to aetures.

l0. hack saw comprising' a holder and a blade, said holderL embracing the blade and bearing iatwise against opposite faces thereto and gripping it, both at the ends and at intermittent points, thereby prevent` ing; bending ol the blade, the'blade and holder havingl registering apertures at the ends of the blade, and a elan'ipingl means passingthrough said apertures and eonstituting the sole means for securing' the holder and blade in grippingl relation, one of said apertures in the holder beingl eX- tended lengthwise of the blade whereby lo adapt the clamping devices to different blades in which the apertures are at respectively dili'ereut distances apart.

ln testimonyv whereof l have afixed my signature.

FREDERICK lV. PIERCE. l 

